This is an application to request an expansion of our Promethion-C continuous calorimetry system, an essential tool to study and analyze small rodent metabolism. The Promethion-C is a parallel continuous system in which each cage is paired with its own flow generator and gas analyzers to record with accurate and high resolution metabolic parameters. The Promethion-C system allows the measurement of precise food and water intake and access, wheel and ambulatory activity and the relative respirometry parameters, RQ, body weight, oxygen consumption, carbon dioxide release and water loss. One year ago, we have acquired through a previously awarded ShEEP grant, a continuous Promethion system equipped with eight cages for small rodents. This has allowed the creation of a new Metabolic and Obesity Research Core at the VAGLAHS to support and facilitate research studies focused on phenotyping metabolic parameters, analyzing appetite, obesity and metabolic disorders, analyzing in detail metabolic responses in animals treated with different composition diets or drug treatments. Currently, there are an overwhelming number of users and experiments that is overburdening our Metabolism and Obesity core. The productivity of the researchers that are using the Promethion-C system at our VAGLAHS is currently limited and the requested 8 cages system expansion would increase the efficiency of our core, enhancing the productivity of all the using investigators. Therefore, we request to expand our core Promethion Continuous System with an addition of eight new cages with sensors, updated software and wheels for physical exercise for all sixteen cages, to evaluate animal metabolism even under the conditions of intense physical stress. The requested expansion of our Promethion-C metabolic system will facilitate the research of our VA investigators, allowing them to study simultaneously up to 16 animals, in such a way completing their experiments in a more timely and efficient manner. Additionally, the new metabolic expanded system will permit more complete metabolic observations even during periods of accelerated and intense physical animal exercise. In the last few years there has been a wide effort from the federal government to promote research in the area of obesity and its associated disorders including diabetes, hypertension, cardiovascular diseases, chronic inflammatory disorders and cancer, due to the accelerating incidence of these disorders in the Veteran and general populations. At our VAGLAHS research department we have several investigators that work in the fields of appetite control, obesity and metabolism disorders. Investigators research capabilities would be greatly enhanced by the use of an expanded Promethion-C calorimetry system that would allow a higher number of researchers to use our metabolic core completing their experiment in a more rapid and efficient fashion. We feel that our request of expanding the only equipment to study animal metabolism and obesity at the VAGLAHS, will increase enormously the productivity of our research core and fulfill the VA and federal government efforts to promote and facilitate research in the area of obesity and its associated disorders to improve the Veterans and general population health, decreasing the financial economic burden that the cure of these diseases in the current and future generations requires.